Mold for swimming pools



1959 B. M. LIFTER. ETAL 2,910,759

MOLD, FOR SWIMMING POOLS Filed Feb. 14, 1957 a Sheets-Sheet 1 1N VENTOR M. Lifter Russell R.Seul,dr.

ATTORNEY Nov. 3, 1959 Filed Feb. 14, 1957 FIG.2

B. M. LIFTER ETAL MOLD FOR SWIMMING POOLS 3 Sheets-Sheet 2 INVENTOR Bennett M. Lifter Russell R.Seol, Jr: Z M

ATTORNEY Nov. 3, 1959 B. M. LIFTER ET AL MOLD FOR SWIMMING POOLS 3 Sheets-Sheet 3 Filed Feb. 14, 1957 INVENTOR Bennett M. Lifter Russell RSeol, Jr.

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ATTORNEY United States Patent MOLD FOR SWIMMING POOLS Bennett M. Lifter, Miami Beach, and Russell R. Seal, J12, lVliami, Fla., assignors to Nu-Bilt Homes, Inc., Miami Beach, Fla., a corporation of Florida Application February 14, 1957, Serial No. 640,126

7 Claims. (Cl. 25--124) This invention relates to a mold and more particularly relates to molds for making heavy, cast bodies of concrete, expanded shale aggregate or other suitable materials. The invention is primarily concerned with the problem of making large, heavy bodies such as tanks, swimming pools and the like which customarily heretofore have been cast or formed in situ. By the present invention, an entirely new concept is presented, that of casting and making a finished article of such nature at a factory site in a mold which can be used over and over again, and transporting the finished article to its permanent site.

The building of a swimming pool in situ as heretofore practiced has been'a very expensive undertaking, avail-. able only, for that reason, to a relatively few. Among prior methods of building individual pools or tanks are the following:

(1) An excavation must be prepared at the site and a bottom slab must be poured in each case.

.(2) Then either forms must be prepared for the side and end walls if they are to be of concrete or the like, and steel reinforcement must be placed, or block or brick must be laid, reinforced and faced with stucco, or gunite (sprayed concrete) must be applied to a suitable back form of lumber, steel or block. The building of forms or the erection of lumber, masonry or steel walls on each individual site runs the cost up beyond the reach of the average man.

By contrast, with the mold embodied in the present invention, this cost in labor and material is largely saved, as the mold described herein may be used over and over again, and therefore the cost of a swimming pool, for example, is substantially reduced as compared with the cost of building one according to conventional methods.

An important object of this invention, therefore, is the preparation of a demountable mold for casting large bodies, such as tanks, in concrete, expanded shale aggregate or other suitable materials, removing the body from the mold after its preparation and transporting the object so cast to its permanent site, thereby effecting substantial economies.

A further object of the invention is the preparation of such a mold substantially above the surface of the ground so that the forms may easily be removed from the body after the casting is completed, the cast body removed, and the forms be replaced in position for another pouring.

Other objects and advantages will become apparent as the following description proceeds, and it is to be read in conjunction with the accompanying drawings illustrative of a preferred form of the invention.

In the drawings,

Figure 1 is a plan view of a mold according to the invention.

Figure 2 is a section, with parts in elevation, of a mold formed according to this invention, taken along the line 2-2 of Figure 1.

Figure 3 is a sectional detail taken through a wall of is then poured in as a slab It) with a slightly sloping portion 10a, with more sharply sloping portions 10b, the latter of which converge to form a small well or deep end of the pool. of the slab extend into a substantially plane peripheral,

flanged portion 10d which terminates in a raised shoulder- 10c for a purpose which will be described. A portion 11,

to accommodate a drain in the pool to be poured, may be provided. The slab is preferably reinforced with steel reinforcing rod 12.

This slab 10 forms the base of the mold and will not be disturbed, and it remains in position for consecutive pourings. It will be understood that if a tank 01' body having a difierently designed bottom is desired, a slab 10 would first be poured in conformity with the desired design.

Upon the slab It a layer of an air-permeable fabric 13, such as roofing felt, canvas or other suitable material, is first spread. A substantial layer of an inert, air-permeable, granular material 14 such as sand, fine gravel, crushed rock or even sawdust, is evenly spread. A final protective covering of some substantially strong, impervious material such as building paper 15 is placed over the granular layer. In building a very large pool or tank it may be desirable to use two layers of the granular base, with felt above and below the first layer, as indicated in Figure 4.

These materials form an air permeable support be tween the bottom of the poured tank and the top of the slab which permits the pool to be lifted from the mold after it is completed. The materials specifically mentioned herein are given merely for the purposes of illustration, as other materials having similar properties and which will perform similar functions may be used.

The function of the air-permeable layer 14 is to maintain air circulation between the floor of the swimming pool as poured and the top of the concrete slab form 10. The presence of air prevents suction from occuring between these two bodies to an extent which permits the lifting of the completed pool from the slab form.

The function of the building paper 15 is to prevent the washing away of the air-permeable layer when the aggregate is poured into the mold, and any type of material suificiently resistant to the plastic mix would suffice for this purpose.

The function of the layer of felt is to hold together the granular, air-permeable layer above or below it and to prevent it from being forced out of position by the great weight of the aggregate pour above it.

Within the perimeter of the shoulder lllc of the slab It) the side and end walls of the mold are erected. These comprise inner and outer side walls 17 and 18, and inner and outer end walls 19 and 20, respectively. The walls may be of plywood or other similar materials and are built up in sections (not shown) for ease of handling. These walls are erected with a space 21 between them to receive the plastic aggregate from which the pool will be formed when it is poured. The walls are braced on their outside faces by vertically disposed inner and outer standards 22, 23, respectively, these being tied together by wire or other brackets or bracing (not shown) to prevent spreading when the mix is poured. All interior corners are rounded, as shown in Figures 1 and 3, by bending the plywood around suitable corner round molding 24. The rounding of the corners presents a Patented Nov. 3, 1959 Around its perimeter, the sloping portions pleasing appearance in. the pool and makes it easier to maintainxand keep clean.

The bottom edges of the walls are braced against spreading or shifting by means of a 2x 4- or other medium 25 .which is inserted longitudinally along thebase of the standards between. said standards and the shoulder 100, as .most clearly shown in Figure 3., The end walls aresirnilarly braced, asindicated in Figure 2.

- The upper portions of the walls are braced against spreading by longitudinal and transverse members 26, 27, respectively, which are suitably bolted or clamped to the standards 22, 23, as shown at 22a, 23a, respectively, in Figure 3. It will be noted in this figure that the outer wall is offset outwardly along its upper edge so as to provide a wider ledge or coping 28 along the upper perimeter of the completed pool. Because of this olfset, the outer standards 23 are likewise provided with an offset and the standard is composed of two members, clamped or bolted together as shown at 23b. Diagonal bracing 29,.may further be provided to connect the longitudinal braces with the inner vertical standards 22. The overhead transverse bracing 27 may extend below the longitudinal bracing 26, as indicated in Figures 1 and 2, or. may be above it, as shown in Figure 3, whichever is more convenient or preferred.

. Suitable steel reinforcement 30 may be installed between the walls 17 and 18 and over the paper layer on top of the slab form to reinforce the pool cons-truction.

With the slab form 10 laid on the ground, the side and end walls erected to the desired height and braced, and reinforcing steel fixed in position where desired, the aggregate may be poured, first onto the slab form 10 where it is worked to the desired thickness, contour and finish, and then into the wall forms so that it may blend into and unite with the still soft slab into an integral unit. ,As the slab form 10 has already begun to set, there will be no tendency for it to shift or bulge out under the weight of the pour for the walls. After a reasonable time for the pour to cure and harden, the side and end Walls of the forms are removed and the completely formed swimming pool may be lifted by a crane and placed upon a flat bottomed trailer or other vehicle for transport to its permanent site. The slab 11 remains in position and the side and end walls may be re-installed for another pour.

Changes in the construction and design of invention may be made without departing from the spirit of the invention as defined by the appended claims.

We claim:

1. A mold for casting a complete transportable swimming pool of concrete and like materials, comprising a permanent ground base of set concrete having the shape and profile desired for the bottom of the pool, said ground base having a peripheral flange at substantially ground level, demountable forms erected on said base outlining the body of the pool to be cast, said forms comprising removable, spaced, side and end inner and outer walls supported over and around the periphery ofsaid base, the outer wall of the form resting on said flange, means for bracing said walls at their upper ends to support the plastic load, and an integral shoulder around the perimeter of said flange, said outer walls being braced at their lower ends against said shoulder.

2. A mold according to claim 1, in which an air permeable layer is supported on said base.

3. A mold according to claim 1, in which an air permeable layer is supported on said base and a protective covering is applied over said layer. I

4. A mold according to claim 1, havinga plurality of pool support layers over said base at least one of said layers comprising an air-permeable, granular material, with a cushioning, porous fabric between each layer and a protective covering over the topmost layer.

5. A mold according to claim 1, having a plurality of pool support layers over said base consisting of at least one layer of sand, at least one layer of roofing felt in contact with each layer of sand, and a topmost layer of building paper.

6. A mold for making an integral concrete swimming pool comprising a mold support ground base having the permanent shape and contour desired for the base of the pool and comprising sloping bottom surfaces converging to a lowermost drain area to be formed in the. bottom of the pool to be cast, a permanent mold bot-tom of set concrete forming a hollow mold having the profile and contours desired, and having a peripheral flange at substantially ground level; demountable vertical mold forms supported on said flange and extending upwardly therefrom and peripherally surrounding said permanent mold for receiving concrete to form the sides of a swimming pool, said forms comprising spaced inner and outer walls between which concrete may be poured, the outer Wall resting on said flange, the spacing between said walls communicating with the mold bottom so that concrete poured into said spacing will flow peripherally into said permanent mold bottom to join integrally with the periphery of the pool bottom poured on said mold bottom, to form a complete tank-like, portable concrete pool structure.

7. A mold according to claim 1, having a plurality of pool support layers over said base, at least one of said layers comprising an air permeable, granular material.

References Cited in the file of this patent UNITED STATES PATENTS 720,536 Seamans Feb. 10, 1903 979,863 Leeder Dec. 27, 1910 1,148,246 Marvin July 27, 1915 1,547,530 Stanton July 28, 1925 1,598,332 Vanhouten et al Aug. 31, 1926 1,628,316 Heltzel May 10, 1927 1,937,306 Barriball Nov. 28, 1933 2,296,553 Heritage et al Sept. 22, 1942 2,298,579 Meyer Oct. 13, 1942 

